//=============================================================================
// System  : MatchKit
// File    : EnclosedPattern.cs
// Author  : Fabio Bussu  (matchkit@fabiobussu.it)
// Updated : 04/16/2013
// Note    : Copyright 2013, Fabio Bussu, All rights reserved
//
// This code is published under the Microsoft Public License (Ms-PL). A copy
// of the license should be distributed with the code.  It can also be found
// at the project website: http://matchkit.codeplex.com. This notice, the
// author's name, and all copyright notices must remain intact in all
// applications, documentation, and source files.
//
// Version     Date     Who  Comments
// ============================================================================
// 1.0.0.0  04/16/2013   FB  First draft
//=============================================================================
using System;
using System.Runtime.Serialization;

namespace MatchKit.Patterns
{
	/// <summary>
	/// Provides the logic to match a string enclosed between an opening and a closing string.
	/// </summary>
	/// <threadsafety static="true" instance="false" />
	/// <serialization binary="true" contract="true" />
	/// <conceptualLink target="cb785773-b793-2cc4-acc4-6688cdb226b6" />
	/// <conceptualLink target="0a06b2a9-5f58-409a-ba62-639cfd77bca7" />
	#if DC
	[DataContract]
	#endif
	#if SZ
	[Serializable]
	#endif
	public sealed class EnclosedPattern : BasePattern
	{
		/// <summary>
		/// Initializes a new instance of the <see cref="T:MatchKit.Patterns.EnclosedPattern"/> class. 
		/// </summary>
		/// <param name="open">String to match to open the enclosure. See <see cref="P:MatchKit.Patterns.EnclosedPattern.Open"/>.</param>
		public EnclosedPattern(string open)
			: this(open, open)
		{
			
		}

		/// <summary>
		/// Initializes a new instance of the <see cref="T:EnclosedPattern"/> class. 
		/// </summary>
		/// <param name="open">String to match to open the enclosure. See <see cref="P:MatchKit.Patterns.EnclosedPattern.Open"/>.</param>
		/// <param name="close">String to match to close the enclosure. See <see cref="P:MatchKit.Patterns.EnclosedPattern.Close"/>.</param>
		public EnclosedPattern(string open, string close)
		{
			Open = open;
			Close = close;
		}

		private string _open;
		/// <summary>
		/// Gets or sets the string to match identifying the begin of the enclosing.
		/// </summary>
		/// <serialization member="true" />
		#if DC
		[DataMember]
		#endif
		public string Open
		{
			get { return _open; }
			set
			{
				if (string.IsNullOrEmpty(value))
					throw new ArgumentNullException("value", "Open string must be a non-empty string");
				_open = value;
			}
		}

		private string _close;
		/// <summary>
		/// Gets or sets the string to match identifying the end of the enclosing. 
		/// If this value is null the <see cref="P:Open"/> string will be used.
		/// </summary>
		/// <serialization member="true" />
		#if DC
		[DataMember]
		#endif
		public string Close
		{
			get { return _close; }
			set { _close = value; }
		}

		/// <inheritdoc />
		protected override Match OnMatch(MatchContext context)
		{
			var peeked = context.PeekString(_open.Length, true);

			if (!string.Equals(peeked, _open, StringComparison.CurrentCultureIgnoreCase))
				return Error(context);

			var close = Close;

			context.NextFor(_open.Length);	// skip Open string

			var capture = new Capture(context, true);

			context.NextTo(ch =>
				{
					peeked = context.PeekString(_close.Length, true);
					return !string.Equals(peeked, _close, StringComparison.CurrentCultureIgnoreCase);
				});

			if (char.ToLower(context.Current) != char.ToLower(close[0]))
				return Error(context, "Unexpected end of string");

			var enclosed = capture.ToString();

			context.NextFor(close.Length);	// skip Close

			return Success(context, enclosed);
		}

		/// <inheritdoc />
		public override string HelpString
		{
			get { return "String enclosed between <" + _open + "> and <" 
				+ (string.IsNullOrEmpty(_close) ? _open : _close) + ">"; }
		}
	}
}
